A man of mass 60 kg records his wt. on a weighing machine placed inside a lift. The ratio of wts. Of man recorded when lift is ascending up with a uniform speed of 2 m/s to when it is descending down with a uniform speed of 4 m/s will be

Options

A. `0.5`
B. 1
C. 2
D. none of these

Explanation

To solve the problem, we need to analyze the situation of a man weighing himself in a lift that is moving both upwards and downwards at constant speeds.

### Step-by-Step Solution:

1. **Understanding Weight in a Lift**:
- The weight of a person is the force exerted by gravity on their mass. It is given by the formula:
\[ W = m \cdot g \]
where \( m \) is the mass and \( g \) is the acceleration due to gravity (approximately \( 9.8 \, \text{m/s}^2 \)).

2. **Weight When Ascending**:
- When the lift is ascending with a uniform speed, the acceleration of the lift is zero. Hence, the apparent weight (the reading on the weighing machine) is equal to the actual weight:
\[ W_A = m \cdot g \]
- For a man of mass \( 60 \, \text{kg} \):
\[ W_A = 60 \, \text{kg} \cdot 9.8 \, \text{m/s}^2 = 588 \, \text{N} \]

3. **Weight When Descending**:
- Similarly, when the lift is descending with a uniform speed, the acceleration is still zero. Thus, the apparent weight remains the same:
\[ W_D = m \cdot g \]
- Again, for a man of mass \( 60 \, \text{kg} \):
\[ W_D = 60 \, \text{kg} \cdot 9.8 \, \text{m/s}^2 = 588 \, \text{N} \]

4. **Calculating the Ratio**:
- Now, we need to find the ratio of the weights recorded when the lift is ascending to when it is descending:
\[ \text{Ratio} = \frac{W_A}{W_D} = \frac{588 \, \text{N}}{588 \, \text{N}} = 1 \]

5. **Final Answer**:
- Therefore, the ratio of the weights recorded when the lift is ascending to when it is descending is:
\[ \text{Ratio} = 1 \]